A spatial separation between a read head and a disk platter is often referred to as a “fly height” of the read head. Fly height affects various performance factors in data storage devices, such as hard disk drives. For example, affected performance factors can include, but are not limited to, signal-to-noise ratio (SNR) of readback signals, recording density, and data recovery. Some of these factors can be accounted for by monitoring or controlling fly height. However, it is extremely difficult to directly measure the fly height of a read head due to the closed nature of most data storage devices, rapid movement of the read head relative to the disk platter, and sensitivity to even very small obstructions. It becomes even more difficult to keep track of changes in fly height for data storage devices having a plurality of read heads, such as in two-dimensional magnetic recording (TDMR) hard disk drives.